ISO/IEC DIS 21122-1

Information technology -- JPEG XS low-latency lightweight image coding system

Titre manque

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD
ISO/IEC DIS 21122-1
ISO/IEC JTC 1/SC 29 Secretariat: JISC
Voting begins on: Voting terminates on:
2020-12-28 2021-03-22
Information technology — JPEG XS low-latency lightweight
image coding system —
Part 1:
Core coding system
ICS: 35.040.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/IEC DIS 21122-1:2020(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO/IEC 2020
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

ISO/IEC DIS 21122-1:2020(E)

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









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























            



    



 







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ii © ISO/IEC 2020 – All rights reserved
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ISO/IEC DIS 21122-1:2020(E)
Foreword

   

  

  



    

 
 
    
    
 

 

  

  
    

   
   



   

  









  
  
  
  
      

 

   
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2 © ISO/IEC 2020 – All rights reserved
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ISO/IEC DIS 21122-1:2020(E)
CONTENTS

Foreword ........................................................................................................................................................................................ 2

1 Scope .................................................................................................................................................................................... 9

2 Normative references .......................................................................................................................................................... 9

3 Terms and definitions, abbreviated terms and symbols .................................................................................................... 9

3.1 Terms and definitions ..................................................................................................................................................... 9

3.1.1 9
band 9
3.1.2 10

band type ........................................................................................................................................................................... 10

3.1.3 10
bit 10
3.1.4 10
bitplane 10
3.1.5 10

bitplane count .................................................................................................................................................................... 10

3.1.6 10

bitplane count subpacket .................................................................................................................................................. 10

3.1.7 10
byte 10
3.1.8 10

color filter array ................................................................................................................................................................ 10

CFA 10
3.1.9 10

codestream ........................................................................................................................................................................ 10

3.1.10 10

coefficient group ............................................................................................................................................................... 10

3.1.11 11

code group ......................................................................................................................................................................... 11

3.1.12 11

coefficient .......................................................................................................................................................................... 11

3.1.13 11
column 11
3.1.14 11

compression ...................................................................................................................................................................... 11

3.1.15 11

component ......................................................................................................................................................................... 11

3.1.16 11

continuous-tone image ..................................................................................................................................................... 11

3.1.17 11
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ISO/IEC DIS 21122-1:2020(E)

data subpacket ................................................................................................................................................................... 11

3.1.18 11

(inverse) deadzone quantizer ........................................................................................................................................... 11

3.1.19 11
decoder 11
3.1.20 11

decoding process ............................................................................................................................................................... 11

3.1.21 11

decomposition level .......................................................................................................................................................... 11

3.1.22 12

downsampling ................................................................................................................................................................... 12

3.1.23 12
encoder 12
3.1.24 12

encoding process ............................................................................................................................................................... 12

3.1.25 12

entropy decoder ................................................................................................................................................................ 12

3.1.26 12

entropy decoding .............................................................................................................................................................. 12

3.1.27 12

entropy encoder ................................................................................................................................................................ 12

3.1.28 12

entropy encoding .............................................................................................................................................................. 12

3.1.29 12

grayscale image................................................................................................................................................................. 12

3.1.30 12

filler bytes.......................................................................................................................................................................... 12

3.1.31 12

inverse quantization .......................................................................................................................................................... 12

3.1.32 13

inverse reversible multi component transformation ....................................................................................................... 13

inverse RCT ...................................................................................................................................................................... 13

3.1.33 13

Joint Photographic Experts Group ................................................................................................................................... 13

JPEG 13
3.1.34 13

JPEG XS............................................................................................................................................................................ 13

3.1.35 13
LL band 13
3.1.36 13
lossless 13
3.1.37 13

lossless coding .................................................................................................................................................................. 13

3.1.38 13
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ISO/IEC DIS 21122-1:2020(E)
lossy 13
3.1.39 13

sign subpacket ................................................................................................................................................................... 13

3.1.40 13

significance ....................................................................................................................................................................... 13

3.1.41 14

significance group............................................................................................................................................................. 14

3.1.42 14

significance subpacket ...................................................................................................................................................... 14

3.1.43 14

star-tetrix ........................................................................................................................................................................... 14

3.1.44 14
packet 14
3.1.45 14
padding 14
3.1.46 14
precinct 14
3.1.47 14

precision ............................................................................................................................................................................ 14

3.1.48 14

procedure ........................................................................................................................................................................... 14

3.1.49 14

quantization ....................................................................................................................................................................... 14

3.1.50 14

quantization index............................................................................................................................................................. 14

3.1.51 15

quantization index magnitude .......................................................................................................................................... 15

3.1.52 15
sample 15
3.1.53 15

sample grid ........................................................................................................................................................................ 15

3.1.54 15
slice 15
3.1.55 15

subpacket ........................................................................................................................................................................... 15

3.1.56 15

super-pixel ......................................................................................................................................................................... 15

3.1.57 15

truncation position ............................................................................................................................................................ 15

3.1.58 15

(inverse) uniform quantizer .............................................................................................................................................. 15

3.1.59 15

upsampling ........................................................................................................................................................................ 15

3.1.60 15
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ISO/IEC DIS 21122-1:2020(E)

wavelet filter type ............................................................................................................................................................. 15

3.2 Abbreviated terms......................................................................................................................................................... 15

3.3 Symbols ......................................................................................................................................................................... 16

4 Conventions ....................................................................................................................................................................... 18

4.1 Conformance language ................................................................................................................................................. 18

4.2 Operators ....................................................................................................................................................................... 18

4.2.1 Arithmetic operators .......................................................................................................................................... 18

4.2.2 Logical operators ............................................................................................................................................... 18

4.2.3 Relational operators ........................................................................................................................................... 19

4.2.4 Precedence order of operators ........................................................................................................................... 19

4.2.5 Mathematical functions ..................................................................................................................................... 20

5 Functional concepts ........................................................................................................................................................... 20

5.1 Sample grid, sampling and components ...................................................................................................................... 20

5.2 Wavelet decomposition ................................................................................................................................................ 20

5.3 Codestream.................................................................................................................................................................... 21

6 Encoder............................................................................................................................................................................... 21

6.1 Encoder requirements ................................................................................................................................................... 21

7 Decoder .............................................................................................................................................................................. 21

7.1 Decoding process general provisions .......................................................................................................................... 21

7.2 Decoder requirements................................................................................................................................................... 23

A.1. General ..................................................................................................................................................................... 24

A.1.1. Marker segments and entropy coded data .............................................................................................................. 24

A.1.2. Key to syntax information....................................................................................................................................... 24

A.2. Codestream syntax general provisions ................................................................................................................... 24

A.3. Markers and marker segments ................................................................................................................................ 26

A.4. Syntax description of marker segments ................................................................................................................. 27

A.4.1. Start of codestream .................................................................................................................................................. 27

A.4.2. End of codestream ................................................................................................................................................... 28

A.4.3. Capabilities marker .................................................................................................................................................. 28

A.4.4. Picture header........................................................................................................................................................... 29

A.4.5. Component table ...................................................................................................................................................... 33

A.4.6. Nonlinearity marker................................................................................................................................................. 33

A.4.7. Component-dependent wavelet decomposition marker ........................................................................................ 34

A.4.8. Colour transformation specification marker .......................................................................................................... 35

A.4.9. Component registration marker .............................................................................................................................. 35

A.4.10. Extension marker ................................................................................................................................................ 36

A.4.11. Weights table ...................................................................................................................................................... 37

A.4.12. Slice header ......................................................................................................................................................... 38

B.1. Dimensions of chroma subsampled image planes ................................................................................................. 39

B.2. Division of the subsampled image plane into bands ............................................................................................. 40

B.3. Band indices, horizontal and vertical decomposition levels ................................................................................. 41

B.4. Band existence flags ................................................................................................................................................ 42

B.5. Division of the wavelet-transformed image into precincts ................................................................................... 44

B.6. Division of precincts into lines ............................................................................................................................... 45

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ISO/IEC DIS 21122-1:2020(E)

B.7. Grouping of lines and bands into packets .............................................................................................................. 46

B.8. Division of precinct lines into code groups ........................................................................................................... 50

B.9. Grouping of code groups into significance groups ................................................................................................ 50

B.10. Grouping of precincts into slices ............................................................................................................................ 51

C.1. Entropy decoding general provisions ..................................................................................................................... 52

C.2. Syntax of the precinct .............................................................................................................................................. 53

C.3. Packet header ........................................................................................................................................................... 54

C.4. Packet body .............................................................................................................................................................. 56

C.5. Subpackets ............................................................................................................................................................... 57

C.5.1. Nomenclature ........................................................................................................................................................... 57

C.5.2. Significance subpacket ............................................................................................................................................ 57

C.5.3. Bitplane count subpacket ........................................................................................................................................ 58

C.5.3.1. Purpose of the Bitplane count subpacket .......................................................................................................... 58

C.5.3.2. Bitplane count mode selection for Rl=0............................................................................................................ 58

C.5.3.3. Bitplane count mode selection for Rl=1............................................................................................................ 59

C.5.3.4. Validation algorithm for bitplane count and raw mode override selection..................................................... 60

C.5.3.5. Bitplane count subpacket syntax ....................................................................................................................... 61

C.5.4. Data subpacket ......................................................................................................................................................... 62

C.5.5. Sign subpacket ......................................................................................................................................................... 64

C.6. Bitplane count decoding .......................................................................................................................................... 65

C.6.1. Bitplane count decoding general provisions .......................................................................................................... 65

C.6.2. Computation of the truncation position .................................................................................................................. 65

C.6.3. Computation of the vertical bitplane count predictor and truncation position predictor .................................... 66

C.6.4. Bitplane count decoding for the raw mode. ........................................................................................................... 66

C.6.5. Differential bitplane count decoding for vertical prediction................................................................................. 67

C.6.6. Variable length bitplane count decoding without prediction ................................................................................ 68

C.7. Elementary variable length coding and decoding primitives ................................................................................ 69

C.7.1. Variable length decoding primitive ........................................................................................................................ 69

C.7.2. Variable length encoding primitive ........................................................................................................................ 70

D.1. General ...........
...